Field of the Invention
This invention pertains in general to the field of stimulatory, particularly auditory brain response, and related devices, systems and methods. More particularly the invention relates to an improved system and method for analysing the brain response development and more particularly the invention relates to an improved determination of brainstem response development.
Description of the Prior Art
It is known that auditory brainstem response audiometry can be used for screening test to monitor for hearing loss or deafness. If using complex sound stimuli auditory brainstem response can be used to assess brain stem disorders using sound stimuli. When auditory brainstem methods are used for diagnosis of brainstem disorders they rely on data set of normal healthy subjects for comparisons as a step in the assessments. The assessments may also be time consuming and in most cases can not be performed in real-time. Real-time analysis can be an important tool when evaluating brainstem response state development, such as the affected by certain stimuli, such as psychoactive compounds or substances including psychopharmaceuticals, alcohol, drugs but also therapeutic treatments.
In US 2009/0220426 a method for evaluating an effect of a psychotropic compound or a treatment on a neuronal activity of an animal including determining a change in the amount of information generated by neurons in response to at least one repeatedly applied stimulus. Also provided is a method of screening psychotropic compounds for effectiveness on an animal which involves using a change in sensory discrimination in a population of neurons of the animal, wherein the sensory discrimination is obtained in response to one or more stimuli repeatedly applied to the animal.
The signals were recorded by utilizing surgically implanted arrays of electrodes. All disclosed tests relate to somatosensory and especially investigations of spatial and temporal structure of the receptive field by touching different locations. Even though auditory stimuli is mentioned in the description, it is not disclosed how to use sound stimulus to carry out these investigations.
Post-stimulus time histogram (PSTH) is typically not used in humans. It cannot be applied to determine stimulus induced activity in several parts of the brain simultaneously, as it demands recording of a certain chosen structure. Thus the PSTH is suited for animal research when the researcher knows what part of the brain to look in, but is not a good choice when the researcher wants to see what parts of the brain reacts in relation to a psychoactive compound.
Thus a technique aiming at giving guidance for the researcher, not only the amplitude of the psychoactive drugs effect, but also where it affects the brainstem would be an advantage. It is wanted to compare different parts of the brainstem, without having to position the device in specific neurons, as is the typical case with PSTH.
Hence, an improved device, and a method thereof, for diagnosis of brainstem disorders and/or the influence of a psychoactive compounds or substances on a subject, would be advantageous and in particular a device allowing for a testing procedure that does not rely on any cognitive effort from the subject would be advantageous. Also, improved specificity and reliability of the diagnosis should be more advantageous.